The present invention relates to a new and distinct cultivar of Helleborus that is grown for use as an ornamental plant for the garden and landscape. The new cultivar is known botanically as Helleborus hybrid and will be referred to hereinafter by the cultivar name ‘Walhelivor’.
‘Walhelivor’ resulted from a breeding program that was established by the inventor in 1980 in a cultivated area of Sussex, England. The purpose of the breeding program was to produce new Helleborus plants exhibiting vigorous growth rate, upright form, and flatness of flowers. ‘Walhelivor’ is a hybrid plant that was selected by the inventor in 1995 on the basis of a combination of commercially useful characteristics, including vigor, crop uniformity, plant habit and flatness of flowers.
Commencing in 1980, the inventor assembled and hybridized various Helleborus plants and Helleborus seed strains, including selected seedlings of Helleborus niger ‘Potter's Wheel’ strain, unpatented which the inventor regarded as having promising characteristics of vigor, form and presentation of flowers. Seedlings resulting from each year's hybridizations were grown to first year flowering, and a select number was retained for second year evaluation. By 1995, the inventor had extracted a collection of promising selections from which ‘Walhelivor’ was selected in that year as a single plant. The parents of ‘Walhelivor’ are unknown. ‘Walhelivor’ is derived from plants which have resulted from the hybridization of plants (seedlings) of Helleborus niger, Helleborus×nigercors, and Helleborus×ericsmithii. 
‘Walhelivor’ is a perennial that exhibits vigorous growth, tidy upright habit, large ivory-white flowers, contrasting burgundy-pink buds, and medium-green leaves. The distinguishing characteristics that make ‘Walhelivor’ unique are crop uniformity, vigorous growth rate, tidy plant habit and well presented flat ivory-white flowers that gradually turn pink, then age to green.
The closest comparison plants in commerce, known to the inventor, are the various seed-raised unnamed plant selections which may be listed as, or listed as being from Helleborus niger, Helleborus×nigercors, or Helleborus×ericsmithii. ‘Walhelivor’ is distinguishable from such plants by its vigorous yet tidy habit, its large flowers borne prolifically and which are distinctly ivory-white in color when they open, are tinged pink when mature, and turn green, as they age.
The first asexual propagation was accomplished by the inventor in 1999 in a cultivated area of Sussex, England. Asexual propagation of the new cultivar ‘Walhelivor’ was conducted by the inventor using the method of tissue culture. The unique features of ‘Walhelivor’ proved stable and the plant reproduces true to type in successive generations of asexual propagation.